Hansoh Pharmaceutical's risvutatug rezetecan, a B7-H3-targeted antibody-drug conjugate (ADC) being developed globally by GSK outside Greater China, reduced the risk of death by 54% compared with topotecan in patients with relapsed small-cell lung cancer (SCLC). Full Phase III data from the ARTEMIS-008 trial, presented at the IASLC 2026 World Conference on Lung Cancer in Seoul, showed median overall survival of 18.5 months versus 10.3 months with topotecan (HR 0.46; 95% CI 0.35–0.62; P<0.0001).
The trial was conducted entirely in China and randomized patients 1:1 to risvutatug rezetecan 8.0 mg/kg every three weeks or topotecan 1.2 mg/m² on days 1 through 5 every three weeks. More than 80% of patients had previously received PD-(L)1 inhibitors. Secondary efficacy endpoints also favored risvutatug rezetecan: BICR-assessed median progression-free survival was 7.2 months versus 3.0 months (HR 0.33; 95% CI 0.25–0.42), objective response rate was 58.3% versus 12.6%, and disease control rate was 90.4% versus 60.2%. Grade 3 or higher treatment-related adverse events occurred in 60.9% of patients on risvutatug rezetecan versus 78.2% on topotecan, with hematologic toxicities predominating in both arms.
Risvutatug rezetecan comprises a fully human anti-B7-H3 monoclonal antibody conjugated to a topoisomerase I inhibitor payload. B7-H3 is broadly expressed across SCLC tumors, and receptor-mediated internalization delivers the cytotoxic payload directly to tumor cells — a distinct mechanism from both the checkpoint inhibitors and the bispecific T-cell engager currently approved in this setting.
The data arrive with the China regulatory pathway already in motion. Hansoh Pharmaceutical Group Company Limited (HKEX: 3692), risvutatug rezetecan's originator, filed a biologics license application with China's National Medical Products Administration (NMPA) in September 2026, and the NMPA subsequently included the application in its Priority Review and Approval Procedure. GSK, which holds exclusive global rights outside that territory under a December 2023 licensing agreement, is advancing the molecule globally across multiple tumor types under its EMBOLD development program.